What exactly is solar energy ?

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Solar power is radiant energy that’s produced by the sun. Daily the sun radiates, or sends out, an immense quantity of energy.  The sun radiates more energy in one second than people have used since the beginning of time! The energy of the Sun derives from within the sun itself. Like other stars, the sun is really a big ball of gases––mostly hydrogen and helium atoms.   The hydrogen atoms in the sun’s core combine to create helium and generate energy in a process called nuclear fusion.

During nuclear fusion, the sun’s extremely high pressure and temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. But the helium atom contains less mass compared to four hydrogen atoms that fused. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.

It takes many years for the energy in the sun’s core to make its way to the solar surface, and slightly over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the speed of light.

Simply a small part of the energy radiated from the sun into space strikes our planet, one part in two billion. Yet this amount of energy is enormous. Daily enough energy strikes the United States to supply the nation’s energy needs for one and a half years!

Where does all of this energy go?

About 15 percent of the sun’s energy which hits the planet earth is reflected back to space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar energy also is absorbed by plants, the land, and the oceans. The rest could be employed to supply our energy needs.

Who invented solar energy?

Humans have harnessed solar energy for centuries. Since the 7th century B.C., people used simple magnifying glasses to concentrate the light of the sun into beams so hot they’d cause wood to catch fire. Over a century ago in France, a scientist used heat from a solar collector to produce steam to drive a steam engine.  At first of this century, scientists and engineers began researching ways to use solar energy in earnest. One important development was obviously a remarkably efficient solar boiler introduced by Charles Greeley Abbott, a United States astrophysicist, in 1936.

The solar water heater came into common use at this time in Florida, California, and the Southwest.  The industry started in the early 1920s and was in full swing prior to the second World War.  This growth lasted prior to the mid-1950s when low-cost propane became the primary fuel for heating American homes.

People and world governments remained largely indifferent to the possibilities of solar power before oil shortages of the1970s. Today, people use solar energy to heat buildings and water and to generate electricity. Particularly in light of the disaster in the Gulf of Mexico, we need to be looking more seriously at alternative forms of energy to decrease our dependence on oil – whether foreign or domestic.

This is the first of a two-part series on solar energy contributed by Barbara Young. Barbara writes on www.12voltsolarpanels.net.  her personal hobby website.  Her efforts are related to helping people save energy using solar energy to reduce CO2 emissions and energy dependency. We thank her for her contribution.

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